Confined effects on structural isomers in the MCM-41-SIL matrix as seen by extrinsic probes via PALS and ESR: n-butanol vs tert-butanol
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F21%3A00544637" target="_blank" >RIV/61389013:_____/21:00544637 - isvavai.cz</a>
Result on the web
<a href="https://pubs.acs.org/doi/10.1021/acs.jpcc.1c01951" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpcc.1c01951</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpcc.1c01951" target="_blank" >10.1021/acs.jpcc.1c01951</a>
Alternative languages
Result language
angličtina
Original language name
Confined effects on structural isomers in the MCM-41-SIL matrix as seen by extrinsic probes via PALS and ESR: n-butanol vs tert-butanol
Original language description
The structural–dynamic states of n-butanol (n-BuOH) and tert-butanol (t-BuOH) isomers as representatives of a linear or globular protic polar medium in the bulk and confined states in the Mobile Composition Matter-41 (MCM-41) matrix obtained from the free volume and phase behavior using positron annihilation lifetime spectroscopy (PALS) or differential scanning calorimetry (DSC), respectively, together with the spectral properties and related mobility and interaction of the spin probe (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) using electron spin resonance (ESR), are presented. In the bulk t-BuOH, the typical τ3 vs T response for strongly crystallizing globular organics with a stepwise effect in the vicinity of Tm is found. On the other hand, the bulk n-BuOH exhibits a complicated course depending on thermal cycling due to the distinct crystallization ability of the linear constituents due to their intermolecular H-bonding. Under confinement, both n-BuOH and t-BuOH media in the MCM-41-SIL matrix were amorphized and heterogenized with larger mean free volume sizes and strong broadening of their dispersion with respect to the corresponding bulk states. In addition, very distinct temperature dependences in τ3 vs T/Tg plots with some anomalous effect in the subplateau region in the linear isomer correlating with the DSC response are observed. In the ESR experiment, a drastic difference in the most pronounced characteristic ESR temperature marking a transition from the slow-to-fast-motion regime with the following relations was found: T50G(b) ≅ TmDSC(b) for n-BuOH against T50G(b) ≪ TmDSC(b) for t-BuOH, where TmDSC(b) is the respective melting point. Further, several changes in the TEMPO mobility in both BuOH media are related to the numerous dynamic and thermodynamic transitions as obtained from measured DSC, PALS, and literary viscosity data. Finally, the changes in hyperfine splitting constants of TEMPO sensitively reflect the altered structural–dynamic relationships in both confined BuOH isomers with close coincidences between all three characteristic PALS and ESR temperatures, indicating the same origin of the underlying processes behind the changes in spin probe mobility or free volume expansion.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10404 - Polymer science
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Physical Chemistry C
ISSN
1932-7447
e-ISSN
1932-7455
Volume of the periodical
125
Issue of the periodical within the volume
29
Country of publishing house
US - UNITED STATES
Number of pages
16
Pages from-to
15796-15811
UT code for WoS article
000680445800004
EID of the result in the Scopus database
2-s2.0-85111597830